1. Field of the Invention
The present invention relates in general to a biomolecule chip and a fabrication method thereof. More specifically, the present invention relates to a biomolecule chip and a fabrication method thereof based on Micro-Electro-Mechanical Systems (MEMS) technology, in which the surface of a substrate undergoes a special treatment to facilitate the immobilization of biomolecules thereon.
2. Description of the Related Art
A biomolecule chip is a biological microchip comprising a substrate and biomolecules immobilized on the substrate. Biomolecule chips are often categorized based on the type of biomolecules immobilized on the substrate, for example DNA chips, protein chips, and the like. A biomolecule which is immobilized on a chip and binds with a target biomolecule in a sample for analysis is called a probe. Biomolecule chip-related technical fields for further development include biomolecule immobilization techniques for immobilizing biomolecules on a substrate, binding techniques for binding immobilized biomolecules on a biomolecule chip with a sample, biomolecule detection techniques for detecting the existence and the identity of biomolecules based on the analysis of a biomolecule chip on which unknown biomolecules are immobilized.
Depending on the immobilization pattern of a probe, biomolecule chips can be categorized into microarray chips which have probes immobilized on a solid substrate, and lab-on-a-chips which have probes immobilized on a micro channel.
A recent trend in fabrication technology of biomolecule chips is toward using MEMS technology. When a biomolecule chip is fabricated based on MEMS technology, a functional layer is first formed on the substrate, and then biomolecules are immobilized on the substrate. Considering that many biomolecule chip-related applications must have a platform function, an insulating layer is preferably layered on the substrate of the biomolecule chip. Even though most of the materials used for the insulating layer are hydrophobic, biomolecules immobilized on the biomolecule chip are mostly hydrophilic. This difference often makes it difficult to immobilize the biomolecules on the insulating layer. Therefore, to facilitate immobilization of biomolecules on an insulating layer, it is desirable to develop a surface treatment technology for changing a portion of the surface of the insulating layer in contact with biomolecules to be hydrophilic.